In the field of the dental diagnosis, conventionally, an X-ray panoramic imaging apparatus takes a tomographic image along the curve of a dental arch.
FIGS. 1 and 2 show a conventional X-ray panoramic imaging apparatus.
Referring to FIG. 1, the conventional X-ray panoramic imaging apparatus 1 comprises a rotary arm including an X-ray light source part 20 and an X-ray sensor part 30, and a rotary arm supporting member 50 for supporting the rotary arm.
The rotary arm supporting member 50 includes a rotary arm driving means, thereby rotary driving the rotary arm 30 in a center of a rotary axis 41. In addition, the rotary arm 30 is linearly driven in a length direction of the rotary arm supporting member 50. That is, the conventional X-ray panoramic imaging apparatus 1 takes a photograph a dental arch 60 of a patient with rendering the rotary arm performed as linear driving and rotary driving.
Hereinafter, a method for performing a panoramic photographing employing a conventional X-ray panoramic imaging apparatus 1 will be described referring to FIG. 2.
Once photographing, the rotary arm 30 takes a photograph a photographing point (a) by performing linear driving (Y-axis driving) equivalent to a length direction of the rotary arm supporting member and rotary driving. At this time, the rotary axis 41 is moved to new rotary axis (41-1) and then, the position of the rotary axis 41 is continuously changed (from (41-2) to (41-3) to photograph the dental arch of a patient.
In case of photographing the photographing point (a), an irradiated X-ray is not met with neck cervical vertebrae part of a patient, so that an acquired image becomes clear relatively. However, it is difficult to control an incident angle at a point (a) of an object to be vertical. As a result, there is a problem that the acquired image may be distorted. Furthermore, controlling an enlargement ratio is difficult in photographing tempromandibular joint (hereinafter, referred as a TMJ).
In photographing points (b) and (c) of the object, irradiated X-ray meets neck cervical vertebrae of patient, so that an acquired image is not clear and distorted because it is difficult to render an incidence angle with respect to the photographing points (b) and (c) to be vertical.
Scanning the neck cervical vertebrae is essential in panoramic photographing. Therefore, there are many problems in that an acquired image is unclear and distorted. Controlling enlargement ratio is also difficult.
Various devices and methods for driving a rotary arm in 3-axis direction have been introduced, the above-mentioned problems remains the same.